Silica-gel greases with polymeric additives

From a study of the influence of polyethylene and polyisobutylene on the properties of silica-gel greases, the following have been established: 1. The addition of polyethylene to silica-gel greases improves not only the rheological property indices (yield value, viscosity, oil bleeding, and mechanical stability), but also the service characteristics (antiwear and antiscoring properties, water resistance, adhesivity, and heat-hardening behavior). 2. The addition of high-molecular-weight P-200 polyisobutylene in amounts less than 1% is effective only for the silica-gel greases prepared from the nonpolar naphthenic-paraffinic cable oil S-220. In the silica-gel greases prepared from the aromatic oil PN-6, it is not desirable to use this polyisobutylene, as it produces a substantial deterioration in the strength properties of the grease.